Welcome to CSiBridge

CSiBridge has been created as the ultimate, easy-to-use, integrated software program for modeling, analysis, and design of bridge structures. The ease with which all of these critical tasks can be accomplished makes CSiBridge the most versatile and productive bridge design package in the industry. Welcome to the new world of CSiBridge!!

This topic briefly describes the layout of the program, and thus this help, and directs you to manuals and technical support to help you get started using this latest version of the program.

The topics in the Getting Started book of this Help provide overviews of how to use the program, including an introduction to the Modeling Process, General Process for Creating a Bridge Object, Bridge Analysis,  Nonlinear Static Pushover Analysis, Superstructure Design, Seismic Design, and Bridge Rating. It should be noted that two design processes are available in CSiBridge:  superstructure design (on the Design/Rating tab) and design of the individual elements comprising the structure (the Advanced > Frame Design commands -- the Concrete Frame Design Procedure and Steel Frame Design Procedure).


A CSiBridge model is defined parametrically. The modeling process begins by specifying the basic layout of the bridge (i.e., the length, the bearing, the alignment, the spans, the number of lanes and the lane widths and slopes). Bridge components are then defined:  deck sections, abutments, diaphragms, bents, foundation springs, restrainers, and so on. These components are located relative to the layout to assemble a complete bridge object. Applied  loading, load cases, and superstructure and substructure design, and load ratings are defined for the assembled bridge object. Editable templates and defaults based on bridge-related codes are used to speed model building, analysis, and design. A detailed model of fundamental geometric objects is generated automatically from the bridge object. For unique needs, Advanced modeling options can be used to modify those fundamental geometric objects using Draw, Edit and Assign commands (i.e., the fundamental point, line, and area objects are selected so that materials, properties, loads and other parameters can be assigned to them).

The User Interface

The Orb

The   Orb in the upper left-hand corner of the program window is a key component of the interface. Click the Orb to reveal the commands needed to accomplish the following:

The Orb commands also include the Settings (Units, Tolerances, Database Table Utilities and Settings, Colors, Project Information, Comment Logs and Other Settings such as Graphics Mode, Auto Save, Auto Refresh, Show Bounding Plane,  use positive values on the tension side of a moment diagram, activate Sound, and Show Result Values While Scrolling) and Language options (English or Chinese).

The Orb also can be used to access Resources (e.g, About CSiBridge, this Help, Design manuals, Analysis Reference manual) and to Exit the program.

With a form displayed, depressing the F1 key will display a context sensitive Help topic for the form. The Help Contents provides access to Help topics for windows that do not display "forms." The Help Index provides a listing of topics arranged by keywords.

Customize Quick Access Toolbar

Near the top of the program window, but beneath the title bar and slightly to the right of the top half of the Orb, is a menu bar of icons that can be clicked to perform frequently required tasks. A click on this bar will display the Customize Quick Access Toolbar. Click a command on the list to add it to the menu bar. A check mark preceding a command indicates that the command has been added. To remove a command, click the command to uncheck it. After a command has been added to the menu bar, clicking it will immediately execute the command. An option is also available to change the color – blue, silver, black – used to display the ribbon.


Other commands are grouped under tabs:  Home, Layout, Components, Loads, Analyses, Design/Rating, and Advanced:


Clicking a tab reveals panels, such as the  Wizard, View, Snap, Select, and Display panels on the Home tab:

The panels consist of commands. Click here for a list of the tabs, panels, and commands; click the "+" to reveal the sublevel commands.

Commands and Hover Text

When the mouse is moved over an icon, hover text displays to identify the command and its action. For example, in the following image, the mouse is hovering over the check mark icon to display the hover text for the Home > View > Set Display Options command:

For this example, when the command is clicked, the Display Options for Active Window form shown below displays. Note that the keyboard command (Ctrl+W) command also is shown.


"Type" and "Item" on Panels

Panels on the Components, Loads, and Analysis tabs include Type or Item drop-down lists. The following table identifies the various drop-down lists on each tab and the options available on the drop-down list along with the name of the Panel, which changes depending on the Type/Item selected.


Option Selected

Resulting Panel Name

Components Tab


Material Properties

Frame Properties

Cable Properties

Tendon Properties

Link Properties

Rebar Sizes

Properties - Materials

Properties - Frames

Properties - Cables

Properties - Tendons

Properties - Links

Immediately display Reinforcing Bar Sizes


Deck Sections


Parametric Variations

Superstructure - Deck Sections

Superstructure - Diaphragms

Superstructure - Variations




Foundations Springs



Substructure - Bearings

Substructure - Restrainers

Substructure - Fnd. Springs

Substructure Abutments

Substructure - Bents

Loads Tab





Vehicles Classes


Vehicles - Classes


Response Spectrum

Time History

Functions - Response Spectrum

Functions - Time History

{Load Points}

Point Load

Line Load

Area Load

Temperature Gradient

Loads - Points

Loads - Lines

Loads - Areas

Loads - Temperature Gradient

Analysis Tab



{Load Cases}




Nonlinear Staged Construction

Multistep Static


Response Spectrum

Time History

Moving Load


Steady State

Power Spectral Density


Load Cases - All

Load Cases - Static

Load Cases - Nonlinear Staged Construction

Load Cases - Multistep Static

Load Cases - Modal

Load Cases - Response Spectrum

Load Cases - Time History

Load Cases - Moving Load

Load Cases - Buckling

Load Cases - Steady State

Load Cases - Power Spectral Density

Load Cases - Hyperstatic


Drop-Down List and Panel Names

Some of the Panels also include drop-down lists that can be used to select previously defined layouts, components, loads, bridge objects, load cases, and load combinations. The following table identifies the names of the Panels and drop-down lists on the affected tab. Hover the cursor over the down arrow of the drop-down list  to display a text box showing the name of the drop-down list.



Drop-down list


Layout Line

Current Layout Line



Current Lane


Properties - {Type}

Current Property


Superstructure - {Item}

Current Superstructure Item


Substructure - {Item}

Current Substructure Item


Vehicle / Classes

Current Vehicle


Functions {Type}

Current Function


Loads {Type}

Current Load Definition


Bridge Objects

Current Bridge Object


Load Cases {Type}

Current Load Case


Load Combinations

Current Load Combination


Expand Arrows and Definition Forms

In some instances, the Panel includes a small expand arrow in the lower right-hand corner, as shown in the screen capture below of the Layout Line and Lanes panels on the Layout tab. Note that the expand arrows are highlighted within small circles in this image:

When the mouse is placed over the expand arrow, hover text displays to identify the action that can be completed by clicking the expand arrow. In the following image, the mouse is hovering over the Layout Line expand arrow.

For this image, when the expand arrow is clicked, the Define Layout Lines form shown below displays.

Similarly, when other expand arrows are clicked Define {item} forms display. The Define forms show the previously defined model components and include Add, Copy, Modify/Show, and Delete buttons that when clicked display data forms that are used to manage definitions in the model. Depending on the component being defined, additional buttons may be included, as is the case in this example, which includes the Set Preferences button.

New, Copy, Modify and Delete Commands on Panels

It is possible to bypass the Define {item} forms and go directly to the data form (the same forms that display  when the Add, Copy, or Modify buttons on the Define {item} forms are used) by clicking the Add, Copy, or Modify command on the Layout, Components, Loads, Bridge, Analysis, and Design/Rating panels. The appearance of the commands differs depending on the panel, although each shares small images, as shown in the following figure, which include the Bridge Object, Layout, and Lane panels.

Where and How to Begin

The versatility of the program allows users to begin a model using templates, by importing initial geometry from a variety of formats (Access Database, Excel Spreadsheet, text file, CIS/2, AutoCAD, IFC, IGES,  NASTRAN, STAAD GTSTRUDL,  StruCAD 3D) or "from scratch"  (i.e., the Blank button on the New Model form).

The templates include common bridge types as well as some specialty bridge models (Cable Bridge and Caltrans Bridge). The Quick Bridge Template form enables quick modeling of concrete box girder, concrete tee beam, concrete flat slab, steel I and U girder, and precast concrete I and U girder bridges. When one of these templates is used, the essentials for starting a model (e.g., the layout line, deck section, and bridge object) are defined. Additionally, depending on the template, material properties, frame section properties, bearings, abutments, bents, lanes, vehicles and vehicle classes, load patterns, load case, and other parameters may be defined.

The Bridge Wizard  (on the Home tab) is a step-wise guide through the model creation and analysis process that can be used to tailor a template model or to start a model from scratch. After using a Quick Bridge Template, the Currently Defined Items tree structure on the left-hand side of the Bridge Wizard form will display the definitions that the program has created automatically. To use the Bridge Wizard form to start a model from scratch, use the Orb > New command and then the Blank button followed by the Home > Wizard > Bridge Wizard command.

Alternately, the various commands on the tabs can be used immediately after use of the Blank button on the New Model form to build the model from scratch. The various methods for working with the model can be used interchangeably for all models, except the specialty bridge models (Cable Bridge and Caltrans Bridge). Those specialty model have their own tailored bridge generation processes.

For all bridge types, the commands on the Analysis and Design/Rating tabs should be used to complete analysis and design of the bridge model, including specifying load cases and load combinations, defining superstructure and seismic design requests, and load rating requests.

More information is available, including a Modeling Process, from the Getting Started Book in the Contents of this Help.


If You are Upgrading

About the Manuals

Technical Support